I have one that’s right eye is draining a little bit of clear fluid and goes between being swollen about half way shut, to just slightly swollen. If it were allergies wouldn’t both eyes be effected? I’m thinking a trip to the vet is in the cards. Any suggestions on what may be wrong? I put some drops in it yesterday, doesn’t seem to have helped. 

Could have gotten stung by something. Stuck something in the eye. Veterosyn eye gel is good. 

Could be a plugged tear duct.  

Anything eye related I get my vet out immediately!

When we found Two in this shape when we went to feed, I immediately called my close friend and asked her--she said call vet, which I did.  He had me send pictures and asked questions about what eye looked like inside and several other things.   He told me he felt certain there was something in her eye; he had me rinse with plain water and then put salt water in her eye.   Within 24 hours she was perfectly normal.   But I was ready to load her up to vet's office---eye issues scare me.  

and a good face washing with hands and the water hose and wipe the water away .. horses love to have the "sleepies" wiped out of the corners of their eyes ...  keep in mind a horse has 3 eyelids .. so wash and wipe face/eyes several times 

if you have a 12cc syringe .. fill it with saline solution for human eyes .. stick the stubby nose into the little hole in the horses nose and squirt it up into the tearduct until it is flowing freely ... walla .. you just flushed a tear duct .. 

Always worth it to have the vet check it an eye issue, they can stain it and make sure there isn't a corneal scratch. 

Rinse with human eye solution. Looks like a plugged tear duct if they eyeball itself looks normal. Just flush it out with that twice a day and should be good after one day usually. If not see vet. 

When it comes to eyes, I always determine if the source of swelling is from a foreign object.  If so, I have the vet always look at it. 

Just swollen, like a bee sting, or unknown cause of swelling, I will take a big syringe and flush it real well.  If it is still swollen the next day, I have a vet look at it. 

If I see a blue spot, or any discoloration, a vet looks at it. 

Eyes are nothing to play with. 

Thanks for all of the advice. I am going to rinse his eye with saline solution today, and if not better by tomorrow we are going to the vet!

Excellent plan.  It could be as simple as the horse bumping it  or dust in the eye.  BUT an eye can go bad in a heart beat so nothing to mess with.   

Agree! 

 Do you have alot of flys right now, could be flys bothering him and hes rubbing and made his eye this way.  

My older gelding will get a swollen eye/s from the gnats. If you leave his mask off during day hes miserable. Even cloudy days its got to be on because of them. He shakes his head if they even get near him (or look at him lol)

My mare is totally blind in her right eye and partially blind in her left......I wouldn't wait too long to get it checked out. I make an apoointment anytime I see any watering or squinting but then again I am trying to save what little sight she has left.

I would also keep a fly mask on him. I agree with the others to have your vet look at him.